Virtual sensing system

Abstract

A control system includes an electric heater disposed within an exhaust fluid flow pathway, and a control device for receiving at least one input selected from the group consisting of temperature readings along the exhaust fluid flow pathway, alternator power/current/voltage, battery power/current/voltage/state of charge, IAT and EAT profiles, mass flow rate of an exhaust fluid flow, NH3 slip, TCR characteristics of the heater, alternator speed, engine speed, state of aging of an aftertreatment component, state of aging of engine, aging degradation characteristics, a dosing rate and a temperature of DEF, NH3 storage condition of aftertreatment system, an ambient temperature, and combinations thereof. The control device modulates power to the heater based on the at least one input such that the heater provides different power output as a function of the at least one input and a continuously variable power output during operation of the exhaust system.

What is claimed is: 
     
       1. A control system for a heating system of an exhaust system, the control system comprising:
 at least one electric heater disposed within an exhaust fluid flow pathway; and 
 a control device configured to operate the at least one electric heater and adapted to receive at least one input, wherein the control device comprises:
 a proportional-integral-derivative (PID) controller; 
 at least one of a power output limiter and a mass flow limit table, 
 
 wherein the at least one input relates to an engine condition or a desired temperature profile, and the at least one input includes one or more temperature readings along the exhaust fluid flow pathway, alternator power, alternator current, alternator voltage, battery power, battery current, battery voltage, battery state of charge, a desired engine condition, inlet air throttle (IAT) and exhaust air throttle (EAT) profiles, exhaust gas recirculation (EGR), mass flow rate of an exhaust fluid flow, NH 3  slip, temperature coefficient of resistance (TCR) characteristics of the at least one electric heater, alternator speed, engine speed, state of aging of an aftertreatment component, state of aging of an engine, aging degradation characteristics, a dosing rate of a diesel exhaust fluid (DEF), a temperature of the DEF, NH 3  storage condition of an aftertreatment system, injection timing retard, cylinder cut-out, variable valve manipulation, turbocharger bypass, intake air pre-heating, late post injection, ambient temperature, or combinations thereof, 
 wherein the control device is configured to control the at least one electric heater to provide a continuously variable heating output, 
 wherein the control device is further configured to calculate a temperature, provided as a calculated temperature, based on the at least one input, 
 wherein the control device is configured to control the at least one electric heater to provide a first power output based on the calculated temperature and the PID controller in response to the calculated temperature being greater than a calculated temperature threshold value, and 
 wherein the control device is configured to control the at least one electric heater to provide a second power output greater than the first power output to increase heating output based on the at least one of the power output limiter and the mass flow limit table in response to the calculated temperature being less than the calculated temperature threshold value. 
 
     
     
       2. The control system according to  claim 1 , wherein the one or more temperature readings include a selective catalytic reduction (SCR) inlet temperature, and wherein the control device is configured to operate the at least one electric heater to provide a higher heating output when the SCR inlet temperature is below a SCR threshold value than, when the SCR inlet temperature is above the SCR threshold value. 
     
     
       3. The control system according to  claim 2 , wherein the control device is configured to provide at least one of a magnitude and a rate of power increase to the at least one electric heater to provide the higher heating output. 
     
     
       4. The control system according to  claim 1 , wherein the at least one input further includes a temperature profile based on the engine condition, including a temperature-mass flow profile, a temperature-engine speed profile, a temperature-load profile, or a temperature-engine condition profile. 
     
     
       5. The control system according to  claim 1 , wherein the at least one input includes the battery state of charge, and the control device is configured to reduce power provided to the at least one electric heater when the battery state of charge is lower than a battery threshold value. 
     
     
       6. The control system according to  claim 1 , wherein the control device is configured to pulse power to the at least one electric heater to control current supply. 
     
     
       7. The control system according to  claim 1 , wherein an engine calibration is modified to supply additional heat along with operation of the at least one electric heater when more heat is needed. 
     
     
       8. The control system according to  claim 1 , wherein the at least one input includes the NH 3  slip, and the control device is configured to operate the at least one electric heater to provide a lower heating output when the NH 3  slip is greater than an NH 3  threshold value than when the NH 3  slip is less than the NH 3  threshold value. 
     
     
       9. The control system according to  claim 1 , wherein
 the at least one input includes the temperature reading along the exhaust fluid flow pathway, 
 the control device is configured to compare the temperature reading to a temperature reading threshold value, and 
 the control device is configured to provide power to the at least one electric heater based on the PID controller when the temperature reading is above the temperature reading threshold value and based on the at least one of the mass flow limit table and the power output limiter when the temperature reading is below the temperature reading threshold value.